mysql恢复报ERROR 2006 (HY000) at line 5303856: MySQL server has gone away错误处理

一、问题描述
  mariadb 10.1.16

  centos 6.6

在恢复binlog时，报错：

[apps@abc backup]$ time /apps/svr/mariadb10/bin/mysqlbinlog mysql-bin.000096 --start-datetime='2017-03-31 01:01:41'|/apps/svr/mariadb10/bin/mysql -u root -p  --

socket=/tmp/mysql3306.sock

Enter password:

ERROR 2006 (HY000) at line 5303856: MySQL server has gone away

real    3m43.697s

user    0m21.772s

sys     0m12.850s

二、问题分析
  查看相关参数如下：

MariaDB [(none)]> show global variables like '%timeout%';

+-----------------------------+----------+

| Variable_name               | Value    |

+-----------------------------+----------+

| connect_timeout             | 10       |

| deadlock_timeout_long       | 50000000 |

| deadlock_timeout_short      | 10000    |

| delayed_insert_timeout      | 300      |

| innodb_flush_log_at_timeout | 1        |

| innodb_lock_wait_timeout    | 45       |

| innodb_rollback_on_timeout  | OFF      |

| interactive_timeout         | 28800    |

| lock_wait_timeout           | 600      |

| net_read_timeout            | 3        |

| net_write_timeout           | 6        |

| slave_net_timeout           | 30       |

| thread_pool_idle_timeout    | 60       |

| wait_timeout                | 28800    |

+-----------------------------+----------+

14 rows in set (0.00 sec)

其中lock_wait_timeout为300秒，wait_timeout为28800秒，参数设置不小，再查看 max_allowed_packet参数大小为67M，大小还好。

MariaDB [(none)]> show variables like '%packet%';

+--------------------------+------------+

| Variable_name            | Value      |

+--------------------------+------------+

| max_allowed_packet       | 67108864   |

| slave_max_allowed_packet | 1073741824 |

+--------------------------+------------+

2 rows in set (0.00 sec)

通过业务表查询恢复到的时间点为2017-03-31 15:32:51,如下：

MariaDB [md_sl]> select modify_time from gtyr order by modify_time desc limit 1,5;

+---------------------+

| modify_time         |

+---------------------+

| 2017-03-31 15:32:51 |

| 2017-03-31 15:32:51 |

| 2017-03-31 15:32:51 |

| 2017-03-31 15:32:51 |

| 2017-03-31 15:32:51 |

+---------------------+

5 rows in set (0.64 sec)

而mysql-bin.000096 binlog文件最后生成时间为15:32，时间点上刚好一致。

[apps@abc backup]$ ls -lt

total 1112044

drwxr-xr-x 8 apps apps      4096 Apr  4 18:38 xtrabackup_20170331010001

-rw-rw---- 1 apps apps 260286601 Apr  4 18:35 mysql-bin.000097

-rw-rw---- 1 apps apps 676032158 Mar 31 15:32 mysql-bin.000096

drwxr-xr-x 8 apps apps      4096 Dec  8 23:14 xtrabackup_20161207010001

-rw-rw---- 1 apps apps 202401487 Dec  8 23:11 mysql-bin.000064

这个报错ERROR 2006 (HY000) at line 5303856: MySQL server has gone away,应该是恢复没有明确指定一个结束位置，引起恢复未正常退出的报错，但上面这个binlog文件实际上恢复完成。

三、问题解决
   可忽略报错，继续做下一步操作。

[apps@abc backup]$ time /apps/svr/mariadb10/bin/mysqlbinlog mysql-bin.000097 --stop-datetime='2017-03-31 23:59:59'|/apps/svr/mariadb10/bin/mysql -u root -p  --

socket=/tmp/mysql3306.sock

Enter password:

real    0m50.866s

user    0m7.726s

sys     0m3.768s

这里恢复没有再报错。

查询业务表的最新时间：

MariaDB [ss]> select modify_time from gtyr order by modify_time desc limit 1,5;

+---------------------+

| modify_time         |

+---------------------+

| 2017-04-01 00:04:01 |

| 2017-04-01 00:04:01 |

| 2017-04-01 00:04:01 |

| 2017-04-01 00:01:33 |

| 2017-03-31 23:52:01 |

+---------------------+

5 rows in set (0.11 sec)